Self-assembly error correction

Chirality may also be found in assemblies of nonchiral molecules held together by noncovalent forces such as hydrogen bonds or metal coordination. Such bonds are reversible errors in connecting single parts of such an assembly may be corrected, which helps in the construction of larger structures by self-assembly . 

Supramolecular approaches to self-assembly often rely upon reversible noncovalent interactions. These strategies inherently involve an error-correction process, and as a consequence, the thermodynamically Savored structures are preferentially constructed.Particularly in the self-association of racemic components, the error-correction process often leads to the selective formation of the homochiral clusters, although the diastercomcric clusters with similar stability are potentially formed as the final products. ... 

The tendency of porphyrins to form aggregates, and the structural control of the assembly formed can be directed by the help of axial binding in the case of metalloporphyrins. In this section we will first examine examples in which the axial bond formed is a coordination bond for which dissociation is still possible. The formation of reversible bonds in self-assembled processes is extremely important because it permits the use of combinatorial type approaches, and leaves the possibility of correcting errors that may have occurred during the assembly process. Such synthetic design features usually afford thermodynamically stable scaffolds instead of a more or less random assembling of the chromophores. 

Jiang, W, Schafer, A., Mohr, PC., Schalley, C.A. (2010) Monitoring Self-sorting by Electrospray Ionization Mass Spectrometry Formation Intermediates and Error-correction during the Self-assembly of Multiply Threaded Pseudorotaxanes. J. Am. Chem. Soc. 132 2309-2320. 

Consequently, the symmetry may be lower and the structural characterization can be a challenge. As we show, MS contributes its share here, but the focus is again on the solution-phase reactivity. Self-sorting includes the possibility that assembly errors occur, which need to be corrected. MS is able to detect these errors and follow the error correction steps. 

Error checking The complementarity of shape and electrostatic field of subunits constituting the assembly forms the basis for the recognition process. It provides for self-checking and excludes defective subunits thus correcting occasional synthetic errors. 

The orbackground concept for calculating resonance self-shielding the capture and fission resonances may be in error by 0.1 to 0.2% in kg the errors due to an improved correction for anisotropic down scattering are about as large. These relatively small corrections cannot account for the large discrepancies observed for Pu-fueled assemblies. The recent and probably more reliable results for o-Pu will give only a small improvement. 

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